The present invention relates to machines for cleaning and/or peeling various fruits and vegetables (produce) by rotating the produce in a drum with sufficient velocity to drive the produce outwardly against a cleaning/abrading surface, spindles or the like.
It has long been recognized that the cleaning and/or peeling of produce at a high rate with minimal waste and handling damage is important in the food processing industries. Attempts to accomplish this have presented difficult problems due to many factors, including the highly irregular surfaces of certain produce, such as potatoes, the substantial variation in optimum abrasive surface pressure for different types of produce, the susceptibility of some produce to handling damage, differences in epidermis characteristics of different produce types and different species of the same type, the ever increasing difficulties in disposing of waste wash water and treating chemicals and the recent substantial increase in the cost of energy for producing steam, hot water or radiant heat for certain related operations.
High capacity produce peeling and cleaning devices have been utilized for many years, as exemplified in U.S. Pat. Nos. 2,355,810 and 3,811,000. Such devices relied upon gravitational tumbling of produce groups in a peeling cage constructed of elements with an abrasive surface and having a revolving auger therein for moving the tumbling groups therealong. A new concept was presented in U.S. Pat. Nos. 4,062,895 and 4,068,574 wherein the peeling cage accelerated the produce to a rotary speed sufficient for maintaining the produce in continuous contact due to centrifugal force against a rotating spindle abrading surface. This greatly improved the potential cleaning and/or peeling efficiency by presenting a manyfold increase in active abrasive surface area within the cage along with the pressure acting on the produce, while also permitting highly accurate control of produce pressure thereagainst by merely varying the cage speed. Further, the new arrangement reduced the likelihood of produce damage by substantially decreasing tumbling.
Further improvements upon the prior art were presented in applicant's U.S. Pat. Nos. 4,230,034 and 4,258,069. The difficulty in accurately controlling the residence time of produce within the treating cage was overcome by the introduction of an auger or spiral fall inhibiting arrangement. The auger was used to resist or retard the gravitationally induced downward travel of the produce. In addition, certain variations of the abrasive surface were incorporated to provide for efficient and appropriate treatment of a great variety of fruits and vegetables.
Although the improved methods and apparati disclosed in U.S. Pat. Nos. 4,230,034 and 4,258,069 were marked improvements over prior devices, some difficulty was experienced in controlling certain products flowing through the machine. In particular, produce was sticking, bunching, bridging or clustering in certain spots, if a steady centrifugal force was applied. Additional product flow problems sometimes resulted from the spindles corotating at the same speed and, in particular, spherical or cylindrical shaped produce had a tendency to spin and not be abraded as desired.